Under NM drinking water regulations, how many total coliform compliance samples must be collected per month by a community water system?

• A. 2
• B. 3
• C. 4
• D. 5

Answer: (B)

The key idea is the baseline amount a community water system must monitor each month to reliably check for coliform presence. In New Mexico, the standard monthly requirement is three total coliform compliance samples for a community water system. This number strikes a balance between catching intermittent contamination and keeping sampling practical. Collecting fewer than three would weaken the monitoring effort and could miss contamination events, while collecting more than three isn’t the default obligation unless a system has specific circumstances or regulatory triggers. If any sample does test positive for total coliform, the system will then follow the required repeat-and-response steps, but the routine minimum remains three samples per month.